A principal component of the wound healing process is the restoration of structural and functional integrity to the injured tissue, which involves the extensive biosynthesis, deposition and remodeling of collagen. Previous investigations into collagen metabolism in tissue repair have dealt primarily with collagen biosynthesis and deposition alone. Consequently, the physiological role of collagenase in wound healing is mostly speculative. The overall objective of this study is to examine collagenase in tissue repair. This will encompass the determination of enzyme activity, enzyme distribution, and the cell source of this enzyme during wound healing. Collagenase to degrade different colagen types will be examined. The purified collagenase will be used to produce highly specific monoclonal antibodies through hybridoma technology. These antibodies will be employed to immunohistochemically localize each type of collagenase in tissue sections from an in vivo wound model. With the monoclonal antibodies directed against collagenases from different sources, and a recently developed collagenase assay, the stated objectives of the stuty should be achieved. In vitro studies will be performed examining the effect of the inflammatory cvell mediators PDGF and IL-1 on dermal fibroblast synthesis of collagenase. These studies will use the in vitro translation of extracted m-RNA in addition to the secreted enzyme activity. This information will enable one to examine the translational control of procollagenase synthesis. The modulation of extracellular collagenase activity by the serum inhibitor alpha-2-marcorglobulin will be studied to determine the physiological relevance of this interaction. These studies are essential to the understanding of normal wound healing, with the proposed experiments examining the in vivo relationship of collagenase to this basic physiological process. With this information, it will be possible to examine such disorders as hypertrophic burn scars, keloid and ulcers, which may result from alterations in normal collagenase regulation. In addition, the clinically apparent effects of steroids on wound healing may be produced by a pharmacological interaction of these compounds on collagenase regulation. These studies are all dependent on the information derived from this proposed investigation.